Although I'm running Windows 10 Insider build 14951, this same problem has existed for the last several builds.

What is happening on my system is that 10-15 seconds after the window 10 boot is...

I have Windows 10 installed on one HD and running well.

I've just added a second formatted HD where I wish to install Windows 7.

My question - should I first disconnect the Windows 10 HD before...

Thanks for the suggestion, will give it a try.

Jim

Win7 now works fine. After the install was complete I shut down and re-connected my Windows 10 HD.

On start up, I went into the bios setup (enter key) and changed the drive order to Windows 10,...

Will give that a try and get back to you soon.

Jim

No it is not a GPT drive, it is an older type HD.

I have Windows 10 installed on HD1 (Samsung) and working will.
I had a second HD2 (WD) with Win7 installed for a dual boot operation.
For some reason, I could never successfully boot into Win7....